In current electronic circuits, the use of increasingly higher speed switching signals has necessitated control of impedance for signal transmission. Also of importance is the need for shielding between the designated signal contacts to prevent from cross talk interference between the adjacent contacts.
At the connector interfaces between motherboards and daughterboards, this has been accomplished primarily by alternating ground terminals with signal terminals in the connectors in order to provide a signal reference path in shielding for the signal path. Traditionally, large numbers of terminals are used for ground, with as many as eight terminals being used as ground for every one that is used for signal. Thus, in the prior art, the number of terminals used for signal transmission is drastically limited, which in turn limits the amount of contact areas which can be beneficially connected between the motherboard and daughterboard for signal connection purposes.
It too is important to provide for an easily manufactured connector with the availability for other options such as exterior RFI/EMI shielding, keying and the like without complicating the system.